1. Technical Field
The present invention relates to a liquid ejecting apparatus including a liquid ejecting head for ejecting a liquid onto a liquid-ejection-target medium.
2. Related Art
An ink jet recording apparatus such as an ink jet printer or a plotter has an ink jet recording head which is capable of ejecting ink as an ink droplet, the ink being stored in a storage unit such as an ink cartridge or an ink tank.
The ink jet recording head has a pressure generating chamber that is in communication with a nozzle opening and a pressure generating unit for generating a pressure change in the pressure generating chamber to eject an ink droplet from the nozzle opening. Examples of the pressure generating unit mounted on the ink jet recording head include a longitudinal vibration type piezoelectric device, a flexural vibration type piezoelectric device, a heat generating device, and a unit using electrostatic force.
In JP-A-2004-223962 and JP-A-5-31893, ink jet recording apparatuses are proposed in which a heating unit such as a heater heats a platen to dry ink ejected onto a recording sheet.
In JP-A-2004-142166, an ink jet recording apparatus is proposed, which is provided with a blower unit for blowing air onto a surface of a recording sheet on which printing has been performed.
In cases where a heating unit is provided in order to dry ink, the ink jet recording head is heated by the heat produced by the heating unit, so that a volatile component of ink in the vicinity of the nozzle opening is evaporated. Thereby, viscosity of the ink in the vicinity of the nozzle opening is increased, leading to a risk that unstable ejection will be caused due to the thickened ink. In addition, there is a disadvantage that further drying of the ink causes clogging of the nozzle opening.
In the case where there are ink droplets and ink mist adhered to a nozzle plate, they are dried by the heat and the viscosity of the adhered ink is thereby increased. Furthermore, dust is adhered to the ink, so that the ink is adhered as a foreign object in the vicinity of the nozzle opening, resulting in disadvantages such as clogging of the nozzle opening and defective liquid ejection, that is, it is difficult to eject an ink droplet in a predetermined direction when ejection has started.
Furthermore, in cases where the ink jet recording head is heated, an adhesive adhering to each member configuring the ink jet recording head is degraded due to variation in the coefficient of thermal expansion of each member, or the heat helps a solvent contained in ink to degrade of a component of the recording head and the adhesive. Consequently, there is a disadvantage that durability of the ink jet recording head is decreased.
Such disadvantages are not limited to ink jet recording apparatuses, but similarly exist in liquid ejecting apparatuses for ejecting liquids other than ink.